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Topic: Virtual only machine? (Read 4952 times)

I was asked a question yesterday about Type 1 Virtual Machine software. Basically the user wants to have a computer with no OS running but boot up and be able to choose from a list of virtual machines to run. From my infinite knowledge (Wikipedia) I think this is a type 1 hypervisor or Kernel-based Virtual Machine (KVM).

I have a fair bit of experience with VMs using VirtualBox on my desktop to test new distros etc...

Does anyone here have any insight or advice on a Virtual only machine as explained above? I read about Xen and I will have a play around with it myself but any help would be appreciated.

Mmm, it sounds more like he's looking for a multi-boot system rather than VM's (!)You can install multiple OS's in parallel, then have the machine offer a boot menu that will boot your chosen OS.[this is a function of the "GRUB" bootloader]

VM's are a little different in that you boot the OS (whether this be a real OS or a hypervisor), then you can run a number of instances of a.n.other operating system on top, in parallel.

In Xen speak , you would boot the machine into the OS which would be Xen Dom0, which is a cut-down / bastardized version of the Linux kernel, or with KVM you'd boot a standard Ubuntu (or whatever) kernel. Then in either instance you could run one or more instances of other Operating Systems on top.

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Note :: XEN has one use and one use only, it runs on pre HVM machines, i.e. kit that's typically > 3-4 years old. You'd either have to have a very specific technical reason to run it in preference to KVM, or some really old kit, or a common sense deficiency ...

General outline of how to get a Windows instance up using KVM on an Ubuntu machine;

Make sure you have "kvm" and "virt-manager" installed.Insert your windows install disk and do;

Run virt-manager, connect to the local machine, create a new instance, select windows.img as the "install CD", create yourself a virtual disk, follow the instructions and it should get the VM running. Double click on the entry in virt-manager and it should present a console showing the Windows installation screen .. then just install as you would a normal Windows machine .. albeit a Windows machine running in a Window.